Okay, so I finally broke down and went to the doctor. Diagnosis: "your heel is pretty inflamed." That's actually good news. The x-ray didn't show anything. Next week, I'll get an ultrasound, to look at soft tissue. In the meantime, she suggested and we're now trying a "homeopathic injection." Apparently, it's injectable "Traumeel". I've used Traumeel before, and it seemed to help, so here's hoping that injecting it in about 8 places (ouch, ouch, ouch) will help even more.
No running until after the ultra-sound, but they seem to have a menu of treatments to try. Woohoo!!